"Legal Complaint Scam, Serve You In 48 Hours." It's a BS scam to get you to contact the main scammer. Don't answer. Could be based on a zombie debt your not responsible to pay. Certainly not to illegal call practices.
310-579-6126
323-699-3325
406-905-0533
406-905-0537
435-554-7012
702-757-2052
888-557-1980 <=Primary scammer
971-888-7704

Possibly related to:
630-599-5060 ARA or FCR